Evaluation of Depositional Mechanisms in Sediment-Hosted Micron Gold Deposits

9523771凯斯勒这项提案要求支持对可在沉积物赋存的微米级金矿床中沉积金矿的过程进行评估。尽管它们很重要，但我们缺乏这些矿石中金沉积的全面模型，这主要是因为我们不了解矿石中金的矿物学形式及其与地质特征的关系。为了评价SHMG矿床固溶/吸附/电化学沉积过程的可行性，我们需要了解：1)不同结构和金含量的黄铁矿的地质背景；2)黄铁矿上的过度生长可以关联的程度；3)金在黄铁矿中的存在形式。回答这些问题的努力将集中在内华达州大型双溪矿床的矿床规模研究上，该矿床含有广泛存在的这里所述类型的黄铁矿结构。工作还包括对内华达州北部古生代沉积岩中黄铁矿的分布进行勘察，以测试先前存在的黄铁矿对金矿沉积的重要性。除了它们对遗传学理论的明显重要性外，这些结果还可以通过在钻探的早期阶段预测等级和划定目标来帮助勘探。

9523771 Kesler This proposal requests support for an evaluation of processes that could deposit gold in sediment-hosted micron gold (SHMG) deposits. Despite their importance, we lack comprehensive models for gold deposition in these ores, largely because we do not understand the mineralogical form of gold in the ore and its relation to geologic features. In order to evaluate the feasibility of the solid solution/adsorbtion/electrochemical depositional processes for SHMG deposits, we need to know: 1) the geologic setting of pyrite with different textures and gold contents; 2) the degree to which overgrowths on pyrite can be correlated; 3) the form of gold in pyrite. Efforts to answer these questions will focus on deposit-scale studies at the large Twin Creeks deposit in Nevada, which contains widespread pyrite textures of the type described here. Work will also include a reconnaissance survey of the distribution of pyrite in Paleozoic sedimentary rocks of northern Nevada to test the importance of pre-existing pyrite to gold deposition. In addition to their obvious importance to genetic theories, results could aid exploration by forecasting grades and delimiting targets during early stages of drilling.